Optical fibres have a wide range of applications some of which expose optical fibres to hostile environments. One location at which optical fibres are particularly vulnerable is in the region that the optical fibre emerges from an area in which it is mechanically protected. For example, optical fibres may be attached to or embedded within a substrate and then exit the substrate at a given exit point. At this exit point, the optical fibre is particularly vulnerable to mechanical stresses. Some types of optical fibres are particularly sensitive to mechanical stress, which can damage the fibre or cause interference to the signal carried by the fibre.